sharp_r-8270.pdf

‘D R-8270

SHARP SERVICE MANUAL S7609!?8270J//

COUNTER TOP CONVECTION

MICROWAVE OVEN

MODEL R-8270 In the interests of user-safety the set should be restored to its original condition and only

parts identical to those specified be used.

f TABLE OF CONTENTS

I Page

FOREWORD .................................................................................................................................................... 1

~ THUMB INDEX ................................................................................................................................................ 1

PRODUCT DESCRIPTION .................................................................................................................................. 2

OPERATING INSTRUCTIONS ............................................................................................................................. 3

OPERATION .................................................................................................................................................... 6

SERVICING ................................................................................................................................................... 11

TOUCH CONTROL PANEL ASSEMBLY ............................................................................................................. 19

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ......................................................................... 31

MICROWAVE MEASUREMENT PROCEDURE ..................................................................................................... 36

PICTORIAL DIAGRAM .................................................................................................................................... 37

CONTROL PANEL CIRCUIT ............................................................................................................................. 38

PRINTED WIRING BOARD ............................................................................................................................... 39

PARTS LIST .................................................................................................................................................. 40

PACKING AND ACCESSORIES ........................................................................................................................ 51

SERVICE INFORMATION FOR TOUCH CONTROL UNIT ...................................................................................... 52

SHARP CORPORATION

R-8270

R-8270

SERVICE MANUAL

SHARP

COUNTER TOP

CONVECTION MICROWAVE OVEN

R-8270

FOREWORD

This Manual has been prepared to provide Sharp Corp. Serv-

ice Personnel with complete Operation and Service Informa-

tion for the Sharp Counter Top Convection Microwave Oven,

R-8270.

It is recommended that service personnel carefully study the

entire text of this Manual, so they will be qualified to render

satisfactory customer service.

CAUTION

MICROWAVE RADIATION

Personnel should not be exposed to the microwave energy

which may radiate from the magnetron or other microwave

generating devices if it is improperly used or connected.

All input and output microwave connections, waveguides,

flanges, and gaskets must be secured.

Never operate the device without a microwave energy absorb-

ing load attached.

Never look into an open waveguide or antenna while the device

is energized.

SHARP COPORATION OSAKA, JAPAN

PRODUCT DESCRIPTION

OPERATING INSTRUCTIONS

OPERATION

REPLACEMENT AND ADJUSTMENT

MICROWAVE MEASUREMENT

WIRING

R-8270

PRODUCT DESCRIPTION

ITEMS DESCRIPTIONS

240 Volts

Power Requirements

Microwave Power Outout

Convection Power Output

Case Dimensions

Cooking Cavity Dimensions

EXPLANATIOIN OF MICROWAVE COOKING AND CONVECTION COOKING

The Sharp Convection-Microwave oven uses microwave ener- Materials with a high moisture content, like most foods, will

gy and the sheath heater to produce heat in the food to be absorb microwave energy. As the microwave energy, at a fre-

cooked. quency of 2,450 Megahertz enters the food, the molecules

Unlike conventional ovens, microwave energy will cook foods align themselves with the energy. However, cooking by micro-

without applying external heat. wave energy only, produces no browning or searing (unless cooking a roast of sufficient thickness). This microwave oven

Microwae which are short electromagnetic waves of RF (ra- is, therefore, equipped with a sheath heater to provide brown- dio frequency) energy, pass through materials such as glass, ing of the food.

paper, china, and most plastics. Materials such as metal and The combination of the heater plus high-speed circulation of

aluminum foil tend to reflect microwaves and may be used only air by a circulating fan provides fast cooking and roosting of as recommended in the cooking instructions. foods conventionally with or without the addition of microwave

energy.

SPECIFICATIONS

5.4 Amperes (Microwave)

6.7 Amperes (Convection)

50 Hertz

Single phase, 3 wire grounded

650 watts nominal of RF microwave energy (2 liter water load)

- Operating frequency of 2,450 MHz

1.5 kilo watts

Width 550mm

Height 336mm

Depth 456mm

Width 345mm

Height 208mm

Depth 360mm

Touch Control System

Control Complement

Start pad and Stop/Clear pad

Timer: 99 min. 90 sec.

Clock

Microwave Cook

Convection Cook

Instant Cook

Compu Defrost

Auto Start

Microwave Power for Variable Cooking

Repetition Rate:

HIGH . . . . . . . . . . . . . . . . . . . . . . . . . Full power throughout the cooking time

MED HIGH . . . . . . . . . . . . . . . . . 24 sec. ON, 8 sec. OFF, approx. 70% of high

MED . . . . . . . . . . . . . . . . . . . . . . . . . . 18 sec. ON, 14 sec. OFF, approx. 50% of high

MED LOW (DEFROST)..1 2 sec. ON, 20 sec. OFF, approx. 30% of high

LOW . . . . . . . . . . . . . . . . . . . . . . . . . . 6 sec. ON, 26 sec. OFF, approx. 10% of high

Auto Start Cooking

Weight

Convection Temperature Control Range:

40°C, 70°C, 130°C, 150°C, 160°C, 180°C, 200°C, 220°C, 230°C and 250°C

Approx. 27 kg

2

OPERATING INSTRUCTIONS

/ Auto-TouchTM Control Panel 1

MIX ME0 LOW ME0 HIGH

CJXJV ID @i Ifl ,"I AUTO /Ai 1.1 121 Ifi/ 1~1 COOK coMPu MFROST

P-Steak 3-Rcastbeeflpoh/lamb

whole chlchen 4- Chtchen wces 5 - Pork/Lamb chocs

I TIhkR AUTO START HOLD CLOCK +-

. J

INDICATORS

Indicator lights for Convection KONV), Dual, Variable Cooking, Cook, food doneness (MORE, LESS), kilogrammes (kg), Pound

(Lbs), Ounce (Oz), Auto Cook, Auto Defrost and Temperature

1

(TEMP).

DIGITAL READOUT Shows readout of cooking time, convection temperature, Auto Cook, Auto Defrost Setting, cooking instructions or time of

dFlV.

-L_ COMPU DEFROSTTM PAD

1 Touch to select Compu Defrost setting.

L-- INSTANT COOKTM PAD Touch to cook for 1 minute at HIGH or increase by 1 minute multiples during variable cooking.

- NUMBER AND TEMPERATURE PAD Touch to enter cooking times, clock time or convection temperature.

- CONVECTION COOKING FUNCTION PADS Touch to cook for each function.

I--

VARIABLE COOKING CONTROL PADS Touch to select microwave power setting If not touched, HIGH is automatically selected.

- AUTO START/CLOCK PAD

! Touch to set clock or auto start time.

r

STOP/CLEAR PAD Touch to erase during programming. Touch once to stop operation of oven during cooking; touch twice to cancel cooking programme.

- TIMER/HOLD PAD

I Touch to set minute timer or HOLD (pause) the setting.

- START PAD

I-- Touch to start oven.

R-8270

For more complete information, refer to your Operation Manual.

TO SET CLOCK 1. Touch STOP/CLEAR.

2. Touch CLOCK. m

3. Enter time of day by touching numbers. (Ex. 4:30) 14/[31m

4. Touch CLOCK. i]

TO COOK BY

MICROWAVE 1. Enter cooking time by touching

numbers. (Ex. 1 min. 30 sec.) LmmEl

2. Enter desired Variable Control setting. (Ex. MEDIUM)

r-z---j

3. Touch START. f--ii-J

TO COOK MULTIPLE SEQUENCE BY

MICROWAVE 1. Enter cooking time for 1 st

sequence. (Ex. 4 min. 30 sec.) /4//3(/01

2. Touch Variable Control setting for 1st sequence. (Ex. LOW)

pi---j

3. Enter cooking time for 2nd sequence. (Ex. 5 min.) /5//01/o/

4. Touch Variable Control setting for 2nd sequence. (Ex. HIGH)

/!

5. Enter cooking time for 3rd sequence. (Ex. 8 min.) q Iml

6. Touch Variable Control setting for 3rd sequence. (Ex. MEDIUM) [---G--y

7. Touch START.

TO USE INSTANT COOK 1. Touch Instant Cook.

Use Instant Cook to program one minute of cooking ins- tantly or to increase cooking time while the oven is operating. Great for quick reheating or to adding time without reprogramming the oven.

TO PREHEAT 1. Touch CONVECTION.

riiG.q

2. Touch desired preheat temperature. (Ex. 180°C) /

180°C

3. Touch START. Fi

TO COOK BY

CONVECTION 1. Enter cooking time by touching

numbers. (Ex. 15 min.) 11//5110/m

2. Touch CONVECTION. )I

3. Enter desired cooking temperature. (Ex. 250°C) El

250°C

4. Touch START. r-i&q

TO PREHEAT THEN COOK

BY CONVECTION 1. Touch CONVECTION.

/I

2. Touch desired preheat temperature. (Ex. 180°C) I

180°C

3. Enter cooking time by touching numbers. (Ex. 20 min.) 121/01/01~

4. Touch CONVECTION. riiiLiq

5. Touch START.

4

R-8270

TO COOK BY

AUTOMATIC MIX 1. Enter cooking time by touching

numbers. (Ex. 25 min.)

2. Touch LOW MIX/BAKE or HIGH MIX/ROAST.

3. Touch START.

TO USE TIMER 1. Enter desired time.

(Ex. 3 min.)

2. Touch TIMER.

3. To clear timer, touch STOP/CLEAR.

q loiloi

r?z---j / L”12’x j r--G--j

i STOP

CLEAR I

I J TO CHANGE

TEMPERATURE OF

AUTOMATIC MIX 1. Enter cooking time by touching

numbers. (Ex. 30 min.)

2. Touch LOW MIX/BAKE or HIGH MIX/ROAST.

3. Touch desired temperature. (Ex. 180°C)

4. Touch START.

TO SET AUTO START I. Enter desired start time.

(Ex. 6:OO) Isllolloi (3j/ollo//o/ 2. Touch AUTO START. p3JiF-j HIGH MIX

ROAST

3. Enter desired cooking program. L---l 180°C

/ 4. Touch START. 1/l

I ’ I

SLOW COOK 1. Touch SLOW COOK.

2. Touch desired temperature. (Ex. 13O’=C)

3. Touch START.

GRILLING

pii-iq El 130°C

1. Enter desired time by touching numbers. (Ex. 14 min.)

2. Touch GRILL.

3. Touch START. / I START I

TO USE

COMPU DEFROST

1. Touch COMPU DEFROST.

2. Select desired COMPU DEFROST setting. (Ex. Roast Beef-3)

3. Touch number pads to enter desired weight. (Ex. 1.0 kg round to 3.0 kg)

4. Touch START. During defrosting, oven will stop twice; check food. Touch START to continue defrosting.

COMPU DEFROST CHART

jetting Food Weight

;

L2.l ml 0 to 3.0 kg 3

Whole chicken Roast beef/pork/lamb

/ START /

5

OPERATION

DESCRIPTION OF OPERATING SEQUENCE

The following is a complete description of component func-

tions during oven operation.

OFF CONDITION Closing the door activates both door interlock switches:

upper and lower latch switch.

(In this condition, the monitor switch contacts are opened.)

The stop switch on the lower latch hook is activated by the

lower latch head.

When oven is plugged in, the mains supply voltage is supplied

to the transformer on the unit chassis, and the transformer is

energized supplying power to the control unit. But no compo-

nents in the oven will operate except damper motor which will

run until the damper is fully open.

(Figure O-l )

1. All digital readout flashes each second.

To set any program or set the clock, you must first touch

the STOP/CLEAR pad. I:00 will appear on the display and

count up every one minute.

2. A signal is input to the control unit, energizing the coil of

shut-off relay (RY 6).

RY6 contacts close completing a circuit to the damper mo-

tor. The damper motor now operates moving the damper

to the open position, thereby closing the contacts of the

damper switch which inputs a signal to the control unit.

The coil of shut-off relay (RY6) is de-energized, opening

its contacts, thereby turning off the damper motor.

Note: When the door is opened by pushing the door open

button, the oven lamp comes on.

COOKING CONDITION

1. HIGH COOKING

Program desired cooking time and Variable Cooking Con-

trol by touching the TIME pads and the MICROWAVE pad

once.

When the START pad is touched, the following operations

occur: (Figure O-2).

1. The numbers of the digital readout start counting down

to zero.

2. The coil of shut-off relay (RY2) is energized, then the

oven lamp and turntable motor are turned on.

3. The coil of shut-off relay (RY5) is energized, then the

cooling fan motor is turned on.

4.

5.

6.

The coil of cook relay (RY 1) is energized by the con-

trol unit, then the power transformer is turned on.

The mains supply voltage is supplied to the primary

winding of the power transformer and is converted to

3.4 volts A.C. output on the filament winding and ap-

proximately 2400 volts A.C. on the high voltage

winding.

The 3.4 volts A.C. output from filament winding heats

the magnetron filament.

The RF energy produced by the magnetron tube is chan-

neled through the waveguide into the cavity feedbox,

and then into the cavity where the food is placed to

be cooked.

8. Upon completion of the cooking time, the following will

occur:

8-l.

8-2.

8-3.

9.

The shut-off relay (RY2), (RY5) and (RY 1) will be

de-energized, turning off the oven lamp, turnta-

ble motor, cooling fan motor and power trans-

former. Then the generation of microwave energy

by the magnetron is stopped.

The time of day will reappear.

The end of cooking signal will sound, and the

oven will revert to the OFF condition.

When the door is opened during a cook cycle, the in-

terlock switches, stop switch and monitor switch are

activated with the following results. The circuits to the

turntable motor, the cooling fan motor, etc. and the

high voltage components are deenergized, and the dig-

ital readout displays the time still remaining in the cook

cycle when the door was opened.

10. The monitor switch is electrically monitoring the oper-

ation of the upper latch switch and is mechanically as-

sociated with the door so that it will function in the

following sequence.

(1) When the door opens from a closed position, the

upper latch switch open their contacts, and then

the monitor switch contacts close.

(2) When the door is closed from the open position,

the monitor switch contacts first open, and then

the contacts of the upper latch switch close.

If the upper latch switch failes with its contacts closed when

the door is opened, the closing of the monitor switch contacts

will form a short circuit through the fuse and upper latch

switch, causing the monitor fuse to blow.

6

R-8270

2. MED HIGH, MED. MED LOW or LOW COOKING

When the Variable Cooking is programmed, mains supply

voltage is added to the power transformer intermittently

through the contacts of the cook relay which is operated

by the control unit within a 32 second time base.

The microwave power operation is as follows:

HIGH

MED

HIGH

ON 8 set

FF

MED

ON 14 ret MKROWAVE POWER

18sec OFF = Approx 50%

MED ON 20 ret

LOW DEFROST

12 ret OFF I

MICROWAVE POWER

= A~prox 70%

LOW

MICROWAVE PQWkR = Approx 30%

MICROWAVE POWER = Approx 10%

Note: The ON/OFF time ratio does not correspond with the per-

centage of microwave power, because approx. 2 se-

conds are needed for heating of the magnetron filament.

3. COMPU DEFROST COOKING

The COMPU DEFROST key is a special funciton key to

defrost meats and other food faster and better.

COMPU DEFROST 1 to 5 automatically defrosts

beef/pork/lamb joint, sliced loaf, poultry and chicken por-

tions, chops, steaks, minced beef.

Each key has 3 defrost stages.

When the desired COMPU DEFROST number is selected

and the food weight is entered by using the number pad’s,

the oven will cook according to the special cooking se-

quence, refer to Compu Defrost Guide on Operation

Manual.

CONVECTION COOKING CONDITION

Program desired cooking time and convection temperature by

touching the time pad, CONVECTION pad and Temperature

pad.

When the START pad is touched, the following operations

occur:

1.

2.

3.

4.

5.

6.

The numbers of the digital readout start the count down

to zero.

The coil of shut-off relay (RY6) is energized by the con-

trol unit.

2-1. The relay contacts close to provide a current path

to the damper motor.

2-2. The dmaper motor is energized and damper is moved

to the closed position, opening the damper switch

contacts.

2-3. The opening of the damper switch contacts sends

a signal to the control unit de-energizing shut-off re-

lay (RY6) and opening the circuit to the damper

motor.

The oven lamp, turntable motor, cooling fan motor, and

convection motor are energized.

Heater relay (RY4) is energized (if the cavity temperature

is lower than the selected temperature) and the mains sup-

ply is supplied to the heating element.

Upon completion of the cooking time, the audible signal

will sound, and oven lamp, turntable motor, cooling fan

motor, and convection motor are de-energized. At the end

of the convection cycle, if the cavity air temperature is

above 120°C, the circuit to RY5 will be maintained (by

the thermistor circuit) to continue the operation of the

cooling fan motor until the temprature drops below

100°C, at which time relay will be de-energized, turning

off the fan motor. Relay RY3 will, however, open as soon

as the convection cycle has ended, turning off the con-

vection fan motor. This will now cool and allow the damper

door to open.

At the end of the convection COOK cycle, shut-off relay

(RY6) is energized turning on the damper motor. The

damper is returned to the open position, closing the damp-

er switch contacts which send a signal to the control unit,

de-energizing shut-off relay (RY 6).

7

R-8270

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8

R-8270

DESCRIPTION AND FUNCTION OF COMPONENTS

COOLING FAN MOTOR The cooling fan motor drives a blade which draws cooling air

through the oven base. This cooling air is directed through the

air vanes surrounding the magnetron and cools the magnetron

assembly. Most of the air is then exhausted directly through

the back vents. However, a portion of this air through the oven

base. This cooling air directed vapors given off from the heat-

ing foods during microwave cooking. It is then exhausted at

the top of the oven cavity into a condensation compartment.

This fan motor operates during both microwave and convec-

tion cooking.

LOWER AND UPPER LATCH SWITCHES The lower latch switch is mounted in the lower latch hook and

the upper latch switch is mounted in the upper latch hook. They

are activated by the latch heads on the door. When the door

is opened, the switches interrupt the circuit to all components

except the oven lamps, fan motor and control unit.

A cook cycle cannot take place until the door is firmly closed

thereby activating both interlock switches.

UPPER LATCH HEAD

LOWER LATCH HEAD

MONITOR SWITCH The monitor switch, mounted on the upper latch hook, is ac-

tivated (the contacts opened) by the upper latch head on the

door while the door is closed. This switch is intended to render

the oven inoperative by means of blowing the fuse when the

contacts of the upper latch switch failes to open when the door

is opened.

Functions:

1.

2.

3.

When the door is opened, the monitor switch contacts

close (to ON condition) due to their being normally closed.

At this time the upper latch switch is in the OFF condi-

tion (contacts open) due to their being normally open con-

tact switches.

As the door goes to a closed position, the monitor switch

contacts are first opened and then the upper latch switch

contacts close. (On opening the door, each of these

switches operate inversely.)

If the door is opened and the upper latch switch contacts

fail to open, the fuse blows simultaneously with the clos-

ing of the monitor switch contacts.

CAUTION: BEFORE REPLACING A BLOWN FUSE, TEST THE

UPPER LATCH SWITCH AND MONITOR SWITCH

FOR PROPER OPERATION. (REFER TO CHAPTER

“TEST PROCEDURE”)

DOOR OPEN MECHANISM The door is opened by pushing the open button on the control

panel, refer to Figure D-l. When the open button is pushed,

the open plate on the open device pushes in the door lever on

the door, operating the latch head linkage.

The latch heads are moved upward, and released from the latch

hooks. Now, the door will open.

OP/EN BUTTON

Figure D-l. Latch Switches, Monitor Switch and Stop Switch

CONVECTION COOKING SYSTEM This oven is designed with a hot air heating system where food is not directly heated up by the heater, but is instead heated by forced circulation of the hot air produced by the heater. The air heated by the heater is circulated through the convec-

tion passage provided on the outer casing of the oven cavity by means of the convection fan which is driven by the con-

vection motor. It then enters the inside of oven through the vent holes provided on the left and back side of the oven. Next, the hot air heats up the food on the turntable and leaves the oven cavity through the vent hole in the right side of the back cavity. This hot air is reheated by the heater, passes through the convection passage and enters the inside of the oven cavity again, in a continuing cycle. In this way, the hot air circulates inside the oven cavity to raise its temperature pad, at the same time, comes into contact with the food begin cooked. When the temperature inside the oven cavity reaches the preset temperature, the heater is de-energized. When the temperature inside the oven cavity thereafter drops below the preset temperature, the heater is energized again. In this way, the inside of the oven cavity is maintained at approximately the preset temperature. When the timer reaches 0 point, the heater is de-energized and the convection fan stops operating. At the high temperature, the fan motor remains rotating. Au- tomatically the fan motor will be shut down at low temperature.

HEATER The heater is located on the back of the oven cavity as ilius- trated in Figure D-2. It is intended to heat air driven by the convection fan. The heated air is kept in the oven and forcedly circulated and reheated by the heater.

Conrectmn Fan

Convectlo” Fan Motor

Figure D-2.

CONVECTION FAN MOTOR ASSEMBLY The convection fan motor assembly consists of the convection motor, heating element, convection fan etc. and mounting nut. The auxiliary fan is for cooling the convection motor.

The convection fan revolves counter clockwise for forced circulation of hot air produced by the heating element. This hot air circulates inside the oven cavity to raise its temperature and the temperature of the food being cooked.

DAMPER OPERATION Usually, the damper is in the open position except during the convection cooking. Damper position is set automatically by damper motor, damper switch, motor cam and damper arm lever.

These components are operated according to the signal that judges the microwave cooking or convection cooking operation in the control unit.

Microwave Cooking: Damper is in the open position. Because a portion of cooling

air is channeled through the cavity to remove steam and vapors given off from the heating foods. It is then exhausted at the top of the oven cavity into a condensation compartment.

Convection Cooking: Damper is in the closed position, so that no hot air will be allowed to leak out the oven cavity, Figure D-3.

Damper Operation 1. When power supply cord is plugged in:

I-1.

I-2.

I-3.

1-4.

1-5.

When power supply cord is plugged in, a signal is sensed in the control unit, and operates the shut-off relay (RY 6). Contacts of shut-off relay (RY6) close and add the mains supply voltage to the damper motor. The damper motor is energized, opening the damper door. When damper is moved to the open position by the damper cam, damper switch is closed (ON position). The signal of damper switch is re-sensed in the control unit and shut-off relay (RY6) is turned off. The mains supply voltage to the damper motor is stopped and the motor turns off.

2. When oven is microwave cooking: Damper is in the open position.

3. When oven is convection cooking and dual cooking: 3-1. Damper motor is energized by touching START pad. 3-2. When damper is in the closed position (damper switch

is OFF), its signal is sensed by the control unit, and shut-off relay (RY6) is -de-energized.

3-3. The damper is held in the closed position during the cooking operation.

3-4. At the end of the cooking, the shut-off relay (RY6) is energized, and damper is returned to the open position.

NOTE: IF THE DAMPER DOOR IS NOT IN THE PROPER POSI-

TION, ALL FUNCTIONS WILL STOP AFTER 60 SE- CONDS OF OPERATION.

CHECK DAMPER SWITCH AND MOTOR, ADJUST OR REPLACE.

DAMPER DOOR

DAMPER

MOTOR

Figure D-3

DUMPER

SHAFT

DUMPER

DUCT

DAMPER

SWITCH

DAMPER

CAM

10

R-8270

SERVICING

TROUBLESHOOTING GUIDE

When troubleshooting the microwave oven, it is helpful to fol- IMPORTANT: If the oven becomes inoperative because of a

low the Sequence of Operation in performing the checks. Many blown monitor fuse in the primary-monitor

of the possible causes of trouble will require that a specific secondary switch circuit, check the primary and

test be performed. These tests are given a procedure letter secondary interlock switches and monitor

which will be found in the “Test Procedures” section. switch before replacing the monitor fuse.

PROBLEM POSSIBLE CAUSE TEST PROCEDURE OR

CORRECTION

OFF CONDITION

Home fuse blows when power cord Shorted wire in power cord or wire harness. Replace cord or check wiring.

is plugged into wall receptacle.

Monitor fuse blows when power Shorted wire in power cord or wire harness. Replace power cord or check and

cord is plugged into wall receptacle. repair wire harness.

Defective monitor switch. Procedure F.

All digital readout do not appear in No power at outlet. Check home fuse.

display when power cord is first

plugged into wall outlet. Blown monitor fuse. Procedure G.

Blown temp. fuse. Procedure H.

Open wire in power cord, wiring harness, Replace or repair wiring.

or wiring between control panel assembly

units.

Defective control unit. Procedure K.

Defective relay unit. Procedure J.

Display does not operate properly Defective key unit. Procedure 0. when STOP/CLEAR pad is touched.

(Buzzer should sound and time of Defective control unit. Procedure K.

day should appear in display.) Defective relay unit. Procedure J.

Defective stop switch. Procedure E.

Oven lamp does not light with door No power in home. Check wall outlet. opened.

Open wire in power cord or wire harness.

Defective oven lamp.

Defective control unit.

Open or loose wire connection to the

above components.

Blown monitor fuse or temp. fuse.

Replace same or repair wiring.

Replace.

Procedure K.

Check wiring.

Procedure G or H.

11

R -8270

TROUBLESHOOTING GUIDE (CONT’D)


CORRECTION

COOKING CONDITION

Oven lamp does not light in cook

cycle.

(Does light when door is opened)

Oven lamp does not light at all.

Oven lamp lights, but turntable

motor does not operate.

Turntable motor operates

normally but fan motor does not

operate.

MICROWAVE COOKING

Defective contacts of shut-off relay (RY2) Procedure J.

on relay unit.


Burned out bulb. Replace.

Open wiring to oven lamp. Check and repair wiring.

Defective turntable motor. Replace.

Defective cooling fan motor. Check and replace.

Defective shut-off relay (RY5) on relay unit. Procedure J.

Open or loose wiring to the fan motor. Check and repair wiring.

Oven does not go into a cook

cycle when START pad is touched.

Oven seems to be operating but lit-

tle or no heat is produced in oven

load. (Food incompletely cooked or

not cooked at all at end of cook

cycle)

Oven goes into a cook cycle but

extremely uneven heating is

produced in oven load (food).

Oven does not cook properly when

programmed for variable cooking

powers. (Operates properly on

HIGH)

Upper and lower latch switches defective Procedures E.

or out of adjustment.

Defective cook relay (RY 1) on relay unit. Procedure J.


Defective key unit. Procedure 0.

Open or loose wiring to above components. Check and repair wiring.

Defective magnetron. Procedure A.

Defective cook relay (RY 1) on relay unit. Procedure J.

Defective power transformer. Procedure B.

Defective silicon rectifier. Procedure C.

Defective high voltage capacitor. Procedure D.


Open or loose wiring to above components. Check and repair wiring.

Low voltage

Dirty oven cavity

Turntable motor does not operate. Refer to preceding turntable

motor problem.


Defective key unit.

Open or loose wiring between above

components.

Procedure K.

Procedure 0.

Check and repair wiring.

12

R-8270

TROUBLESHOOTING GUIDE (CONT’D)


CORRECTION

Oven does not cook properly when Defective COMPU DEFROST function. Procedure K.

programmed in the COMPU

DEFROST cooking mode.

CONVECTION COOKING

CONV indicator lights but oven

does not go into cook cycle when

START pad is touched.

CONV indicator lights, but heating

element does not heat.

Temperature in the oven cavity is

lower or higher than preset.

Defective key unit.

Defective thermistor.

Open wiring in circuit to above

components.

Defective heating element.

Defective heater relay (RY4) on relay unit.


Open or loose wire connection to the

above components.

Check temperature

Defective heating element.


Defective convection motor.

Defective thermistor.

Defective damper motor.

Defective damper switch.

Defective drive mechanism of convection

fan.

Procedure 0.

Procedure L.


Procedure I.

Procedure J.

Procedure K.


Procedure P.

Procedure I.

Procedure K.

Replace.

Procedure L.

Procedure M.

Procedure N.

Check.

I

13

R-8270

TEST PROCEDURES

PROCEDURE LETTER

A

COMPONENT TEST

MAGNETRON ASSEMBLY TEST

DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COM- PONENTS OR WIRING. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check across the magnetron filament leads should indicate less than 1 ohm.

To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads and chassis ground. This test should indicate an infinite resistance. If there is little or no resistance, the magnetron is grounded and must be replaced.

Power output of the magnetron can be measured by performing a water temperature rise test. This test should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following components or wiring: rectifier, high voltage capacitor, heater transformer and power transformer.

MICROWAVE OUTPUT POWER Microwave output power from the magnetron can be measured by way of substitution, i.e. it can be measured by using water load how much it can be absorbed by the water load. To measure the microwave output power in the microwave oven, the relation of calorie and watt is used. When P (WI heating works for t (second), approximately P-t/4.2 calorie is generated. On the other hand, if the temperature of the water with V (ml) rises AT (“Cl during this microwave heating period, the calorie of the water is V.AT. The formular is as follows:

PG - = V.AT 4.2

P= 4.2 . V AT

(W) t Our condition for the water load is as follows.

Water load . . . . . 2000 ml Heating time . . . . . 120 seconds (2 minutes)

1 P = 70 x AT/

Measuring method; l.Put the water load of two (2) litres on the center of the oven shelf.

The water load should be arranged in two (2) Pyrex beakers, the size of which is one (I) litre, and be placed at right and left, side by side, on the oven shelf.

2. Measure the temperature of water before heating and also after heating during two minutes by microwave, and calculate the temperature rise. The temperature rise should be the average of temperature differences measured in each beaker.

3.The output power should be calculated as follows. In case the measuring result is not satisfactory, execute the measurement several times and judge the result from the synthetic point of view. Microwave output power should be within + 15% of the nominal one.

Calculation of output power; Microwave output power . ..P (W) = 70 x AT (“C)

- AT = (ATL + ATR) 2

: average temperature rise

ATL = (TL2 - TL,) ATR = (TR2 - TR1)

TL2 : water temperature after heating in left beaker TL1 : water temperature before heating in left beaker TRl : water temperature after heating in right beaker TRr : water temperature before heating in right beaker

Measuring condition; As the microwave output is affected by several conditions, the measurement should be made carefully with following attentions. 1. Initial temperature of salt water should be 20 & 1 OC. (The salt water should be contained bon (I) per-

cent of salt.) Well and quickly stir the water and the temperature measurement should be done immedi- ately after heating.

2.The graduation of thermometer should be scaled by 0.1 OC at minimum and an accurate mercury thermometer is recommended.

3. Water container should be one (1 I litre beaker made of Pyrex glass and its diameter approximately 12 cm. 4. Room temperature should be around 20°C. 5. Power supply voltage should be specification voltage.

14

R-8270

TEST PROCEDURES

‘ROCEDURE LETTER COMPONENT TEST

B POWER TRANSFORMER TEST

DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING.

Disconnect the primary input terminals and measure the resistance of the transformer with an ohmmeter.

Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of the primary coil should be less than 1 ohm and the resistance of the high voltage coil should be approximately 82 ohms; and the resistance of filament coil should be less than 1 ohm.

(HIGH VOLTAGES ARE PRESENT TO HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH VOLTAGE.)

C SILICON RECTIFIER TEST


Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance across

the terminals and observe, reverse the leads to the rectifier terminals and observe meter reading. If a short is indicated in both directions, or if an infinite resistance is read in both directions, the rectifier is probably defective and should be replaced.

D HIGH VOLTAGE CAPACITOR TEST


If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads and check for short or open between the terminals using an ohmmeter. Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate continuity for a short time and should indicate an open circuit once the capacitor is charged. If the above is not the case, check the capacitor with the ohmmeter to see if it is short circuited between the terminals. If it is short circuited, replace the capacitor.

E SWITCH TEST

Isolate the switch and check the connection by using the ohmmeter according to the table. If improper operation is indicated, make the necessary switch adjustment or replacement.

Table: Switch Connection

Connection C ommon Terminal-Normally Open Terminal Common Terminal-Normally Close Terminal

Operation KOM) (NO) (COM) (NC)

Plunger released Open circuit Closed circuit

Plunger pushed Closed circuit Open circuit

F MONITOR SWITCH TEST

Before performing this test, make sure that the Primary and Secondary Interlock Switches are operating

properly referring to the Switch Test Procedure. Connect one ohmmeter lead to the Upper latch switch (NO) terminal, and the other lead to the Lower latch

switch (COM) terminal, as shown Figure. When the door is open, the meter should indicate a closed circuit. When the monitor switch lever of the upper latch hook is pushed by a screw driver through the upper latch

hole on the front plate of the oven cavity with the door opened fin this condition the plunger of the monitor switch is pushed in), the meter should indicate an open circuit. In case improper operation is indicated, replace the defective switch.

15

R-8270

TEST PROCEDURES (CONT’D)

PROCEDURE LETTER

COMPONENT TEST

CCO;T’D, MONITOR

G BLOWN FUSE

If the fuse in the upper-monitor switch circuit is blown when the door is opened, check the upper latch

switch and monitor switch according to the Test Procedure of those switches, before replacing the blown fuse.

If the monitor fuse is blown by improper switch operation, adjust or replace the defective switch and fuse

at the same time.

Replace just the fuse if the switches operate normally.

CAUTION; The replacement fuse must be the listed fuse in Parts List.

H TEMP. FUSE TEST

A continuity check across the temp. fuse terminals should indicate a closed circuit.

If the temperature of the magnetron reaches 1 15OC, the temp. fuse opens. If the temp. fuse has opened,

replace the fuse. An open temp. fuse indicates overheating of the magnetron assembly. Check for restrict-

ed air flow to the magnetron through the opening in the chassis, especially the cooling duct.

I HEATING ELEMENT TEST

Make sure the heating element is fully cooled and test as follows;

a. Disconnect wire leads and measure the resistance with an ohmmeter. On the R x 1 scale, the resistance

between the heating element terminals should be approximately 37 ohms.

b. Disconnect wire leads and measure the insulation resistance with 500V - 1 OOMQ insulation resistance

meter.

The insulation resistance between heating element terminal and cavity should be more than 0.5MQ.

J RELAY UNIT TEST

The relay unit consists of circuits including the shut-off relays, buzzer, transformer, etc.

Plug power cord into wall receptacle “88888” will be flashing in the display.

Remove the outer case and check voltage between Pin No. 1 and No. 3 of the 7-pin connector (A) on

the relay unit with an A.C. voltmeter.

The meter should indicate mains supply voltage, if not check oven circuit.

16

R-8270

TEST PROCEDURES (CONT’DI

PROCEDURE LETTER

COMPONENT TEST

J Shut-off, Cook and Heater Relay Test

(CONT’D) These relays are operated by D.C. voltage. Check voltage at the relay coil with a D.C. voltmeter during the microwave or convection cooking operation.

D.C. voltage indicated . . . . . . . . . . Defective relay.

D.C. voltage not indicated . . Check diode which is connected to the relay coil. If diode is good, control unit is defective.

RELAY SYMBOL

RYI (COOK)

RY2

RY3

RY4 (HEATER)

RY5

RY6

OPERATIONAL VOLTAGE

Approx. 14V. D.C.

CONNECTED COMPONENTS

Power transformer

Oven lamp/Turntable motor

Convection motor

Heating element

Cooling fan motor

Damper motor

K TOUCH CONTROL PANEL ASSEMBLY TEST

The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, un-

like conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and

ohmmeter. In this service manual, the touch control panel assembly is divided into two units; key and con-

trol units and troubleshooting by unit replacement is described according to the symptoms indicated.

1. Key Unit.

The following symptoms indicate a defective key unit. Replace the key unit.

a) When touching the pads, a certain pad produces no signal at all.

b) When touching a number pad, two figures or more are displayed.

c) When touching the pads, sometimes a pad produces no signal.

2. Control Unit

The following symptoms indicate a defective control unit. Replace the control unit.

2-l In connection with pads

a) When touching the pads, a certain group of pads do not produce a signal.

b) When touching the pads, no pads produce a signal.

2-2 In connection with indicators

a) At a certain digit, all or some segments do not light up.

b) At a certain digit, brightness is low when it lights up.

c) Only one indicator does not light up.

d) The corresponding segments of all digits do not light up; or they continue to light up.

e) Wrong figure appears.

f) A certain group of indicators do not light up.

g) The figure of all digits flicker.

2-3 Other possible troubles caused defective control unit.

a) Buzzer does not sound or continues to sound.

b) Clock does not operate properly.

c) Cooking is not possible.

d) Proper temperature measurement is not obtained.

Note: When a defective one or more of two components, the Key Unit, or the Control Unit are replaced,

the defective part or parts must be properly packed for return in the shipping carton, with its cushion

material, in which the new replacement part was shipped to you.

17

TEST PROCEDURES (CONT’D)

PROCEDURE j COMPONENT TEST LETTER

--._.. -,

L THERMISTOR TEST

Disconnect the 6-pin connector from the control unit.

Measure the resistance of the thermistor with an ohmmeter. Connect the ohmmeter leads to Pin NO’s 1 and 2.

Room Temp. Resistance

68OF (20°C) - 86’F (3O’C) Approx.

350- 155kg

If the meter does not indicate above resistance, replace the thermistor.

M DAMPER MOTOR TEST

When the power cord is plugged into the wall receptacle, the mains supply voltage is added to the damper

motor and the motor operates until the damper is opened and the damper switch closes. Then the damper

motor stops operating.

If the damper motor does not operate, check for input voltage by A.C. volt-meter at the motor.

I. Disconnect the power cord from the wall receptacle.

2. Disconnect the wire leads of motor and connect the meter leads to the wire leads of main wire harness.

3. Reconnect the power cord into the wall receptacle.

If mains supply voltage is indicated at the wire leads, replace the motor.

Not indicated, check the wire harness and the relay unit.

N DAMPER SWITCH TEST

Disconnect the wire leads from the switch terminals and connect the ohmmeter leads to the common (COM)

and normally open (NO) terminals of the switch.

1. When switch actuator is pushed by the damper motor cam, the meter should indicate a closed circuit.

2. When the power cord is plugged into the wall receptacle, the damper motor operates and damper cam

rotates. The switch actuator is released and meter should indicate an open circuit.

If imporper operation is indicated, replace the damper switch.

0 KEY UNIT TEST

When any indicator does not show response against

key operation, make short-circuit by jumper wire be-

tween the pins for relative key switches for testing,

referring to the following key matrix.

If the indicator responds and oven goes into operation,

the key unit is faulty.

if there is no response, replace the control unit.

P CHECKING TEMPERATURE IN THE CONVECTION MODE

It is difficult to measure the exact temperature in the convection oven. An accurate thermocouple type

temperature meter must be used, A low priced bi-metal type thermometer is not reliable or accurate.

The temperature should be checked approximately 5 minutes after the preheat temperature is reached (au-

dible signal sounds four times.)

The temperature experienced may be approximately 25OC more or less than indicated on the display,

however, in most cases the food cooking results will be satisfactory.

Difference in Power supply voltage will also affect the oven temperature. The household power supply

voltage may sometimes become lower than the rated voltage and cause under-cooking. If the power SUP-

ply voltage is 10% lower than the rated voltage, longer cooking time is required by I 0% to 20%.

18

R-8270

TOUCH CONTROL PANEL ASSEMBLY

OUTLINE OF TOUCH CONTROL PANEL

The touch control section consists of the following units as

shown in the block diagram.

(I) Relay unit

(2) Key unit

(3) Control unit

Exchange of signals between each unit is indicated by the ar-

rows in the block diagram. The principal functions of these

units and the signals communicated among them are explained

below.

Relay Unit Relay unit consists of six Relays (RY 1 -RY6), power source

circuit and buzzer circuit.

Key Unit The key unit is composed of a matrix, signals generated in the

LSIaresenttothekeyunitthroughEll-El3,El5-E17and

E7. When a key pad is touched, a signal is completed through

the key unit and passed back to the LSI through AN4-AN7

to perform the function that was requested.

Control Unit Control unit consists of LSI (lX2429YA), Power source circuit,

Synchronizing signal circuit, ACL circuit, buzzer circuit, ther-

mistor sensor circuit, and indicator circuit.

1)

2)

3)

4)

5)

LSI (IX2429YA)

This LSI controls the thermistor sensor signal, key strobe

signal, relay driving signal for oven function, and indica-

tor signal.

Power Source Circuit

This circuit generates voltage [VC (for IX2429YA): -5V.

VF1: -25V, VF2: -28V, VA: -15V and Vp: -34VI

necessary in the control unit.

Synchronizing Signal Circuit

The power source Synchronizing signal is available in order

to compose a basic standard time in the clock circuit.

It accompanies a very small error because it works on com-

mercial frequency.

ACL Circuit

Circuit to generate signals resetting the LSI to the initial

state when power is supplied.

Buzzer Circuit

The buzzer is responsive to signals from the LSI to emit

noticing sounds (key touch sound and completion sound).

6) Thermistor Sensor Circuit

The temperature in the oven cavity is sensed by the ther-

mistor.

The variation of resistance according to sensed tempera-

ture is detected by the thermistor sensor circuit and the

result applied to LSI.

The result of detecting is given to LSI controlling the re-

lay and display.

7) Stop Switch

A switch to “tell” the LSI if the door is open or closed.

8) Relay Circuit

To drive the magnetron, heating element, fan motor, con-

vection motor, damper motor, turntable motor and light

the oven lamp.

9) Indicator Circuit

Indicator element is a Fluorescent Display.

Basically, a Fluorescent Display is a triode having a

cathode, a grid and an anode. Usually, the cathode of a

Fluorescent Display is directly heated and the filament

serves as cathode.

The Fluorescent Display B-digits, 13-segments are used

for displaying figures.

19

R -8270

3 4 5 6

AL .& I< -r u L 5 E L : 5

5 3 c L? ” ;

: 3 G=5? LL N L cl y. h P

I oi t L---- / w

1 I 2 I 3 I 4 I 5 6

20

DESCRIPTION OF LSI

LS I (IC-1. IX2429YA)

The I/O signals of the LSI (IX2429YA) are detailed in the following tables.

I

EO

El

E2 l----l

3

E22 23 L.-l

vcc

L-l 63 N.C

RI5

R14

RI3

I 59 RI2

55 R8 l---i 54 AN0

/ 53 j AN1

L-i 52 AN2

51 l----i AN3

50 AN4 I I

49 t-----l AN5

48 AN6

47 t-4 AN7

IX2429YA 46 AVcc

1 45 / AVR+

AVR-

AVss

1 42 / E36

38 R5

37 R4

36 R3

i

35 R2

34 Rl

33 RO

Figure T-2. Relationship between pin Nos. and Signals (LSI: IX2429YAI

Pin No. Signal I/O Description

1 EO OUT Digit selection signal. -.--”

.awIb

- The relation between digit signal and digit are I. 2 El OUT as follows:

3 Digit Signal

E2 OUT Digit -24”

EO . . . . . . . . . . . . . . . . . . . . . . . . 1st El . . . . . . . . . . . . . . . . . . . . . . . . 2nd

4 E3 OUT E2 . . . . . . . . . . . . . . . . . . . . . . . . 3rd E3 . . . . . . . . . . . . . . . . . . . . . . . . 4th

1: i!$ mrec.

5 E4 OUT E4 . . . . . . . . . . . . . . . . . . . . . . . . 5th

E5 6th =--l-L-- . . . . . . . . . . . . . . . . . . . . . . . . 6 E5 OUT Normally, one pulse is output in every

p period, and input to the grid of the -A

___-__ Fluorescent Display. Es

21

R-8270

Pin No. Signal I/O Description

7 E6 OUT Segment data signals.

The relation between signals and indicators are as follows: Signal Segment Signal Segment

E6 . . . . . . . . . . . . . . . . . . . . . . . LB El 7 . . . . . . . . . . . . . . . . . . . . . . . . . c

E7 . . . . . . . . . . . . . . . . . . . . . . . UB El8 . . . . . . . . . . . . . . . . . . . . . . . . . b,

E9 . . . . . . . . . . . . . . . . . . . . . . . . . . i El9 . . . . . . . . . . . . . . . . . . . . . . . . . a,

El0 . . . . . . . . . . . . . . . . . . . . . . . . j El 1 . . . . . . . . . . . . . . . . . . . . . . . . k El2 . . . . . . . . . . . . . . . . . . . . . . . h

El3 . . . . . . . . . . . . . . . . . . . . . . . g El4 . . . . . . . . . . . . . . . . . . . . . . . . f

El 5 . . . . . . . . . . . . . . . . . . . . . . . . e El6 . . . . . . . . . . . . . . . . . . . . . . . d

46oH.l i

1

nJ---tye----: :;ix L

zY2=jj Pi~~ox

-34” _/ 1 24 mrc.

ig;n ADP’0i - - - - - - - - -34”

4 1.35 mwc

8 E7 OUT 1) Segment data signal.

Signal similar to E6.

2) Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to AN4-AN7 terminal while one of G-l line keys on key matrix is touched.

9 E8 OUT Segment data signal.


IO E9 OUT Segment data signal.


11 El0 OUT Segment data signal.


12 El1 OUT I) Segment data signal.



Signal applied to touch-key section.

A pulse signal is input to AN4-AN7 terminal while one of G-2 line keys on key matrix is touched.

13 El2 OUT I) Segment data signal.




A Pulse signal is input to AN4-AN7 terminal while one of G-3 line keys on key matrix is touched.

22

R-8270

Pin No. Signal I/O

14 El3 OUT 1) Segment data signal.


Description



A pulse signal is input to AN4-AN7 terminal while one of G-4 line keys on

key matrix is touched.

15 El4 OUT Segment data signal.














18 El7 OUT 1. Segment data signal.



19 El8 OUT

20 El9 OUT

21 E20 OUT




Segment data signal.


Segment data signal.


Terminal not used.

Connected to Vp by bull-down resistor.

22 E21 OUT

23 E22 OUT

24 E23 OUT

25 EX IN

26 X OUT

Terminal not used. Connected to GND.

Internal clock oscillation frequency setting input.

The internal clock frequency is set by inserting the ceramic filter oscillation circuit with

respect to X terminal.

Internal clock oscillation frequency control output.

Output to control oscillation input of EX.

23

R-8270

Pin No. Signal

27 RESET

I/O

IN

Description

Auto-clear terminal. - Signal is input to reset the LSI to the initial state when power is supplied.

Temporarily set to “L” level the moment power is supplied, at this time the LSI is reset. Thereafter set at “H” level.

28 SO E24

29 SI E25

30 E26

OUT

OUT

OUT


Terminal not used.

Signal to sound buzzer.

A: Key touch sound. B: Completion sound. C: When the temperature of the oven cavity

reaches the preset temperature in the preheating mode, or when the preheating hold time (I 5 minutes) is elapsed.

1.24 sec.1.24 sec.

-- -H: GNC

c:

31 IRQ E27 IN Signal synchronized with commercial power source

frequency.

This is the basic timing for all time processing of LSI. _

32 vss IN Power source voltage: -5V.

voltage of power source circuit input.

33 RO OUT Magnetron high-voltage circuit driving signal.

To turn on and off the cook relay fRYI). In HIGH operation, the signals holds “L” level during microwave cooking and “H” level while not cooking. In other cooking modes (MED HIGH, MED. MED LOW, LOW) the signal turns to “H” level and “L” level in repetition according to the power level.

34 RI

HOLD ”

OUT Oven lamp and turntable motor driving signal (Square waveform: 50Hz).

To turn on and off shut-off relay (RY-2):

The Square waveform voltage (50Hz) is delivered to the RY2 driving circuit and RY1. RY4 control circuit.

A: 10.2 msec. B: 9.8 msec.

24

Pin No. Signal

35 R2

I/O

OUT

Description

Heating element driving signal.

To turn on and off the heater relay (RY4). “L” level during convection cooking; “H”

level otherwise.

the signal becomes “H” level when the l-xz%:~:~~~~ : GNC * During convection cooking or MIX cooking,

r,N temperature of the oven cavity exceeds

the predetermined temperature.

36 R3

37 R4

OUT

OUT

Cooling fan motor driving signal.

To turn on and off shut-off relay (RY5). ‘IL” level during both microwave and convection - H: GNO

cooking; “H” level otherwise. * During

OFF

w cooking

ON -------L

CONVECTION MOTOR driving signal.

To turn on and off shut-off relay (RY3). “L” level during CONVECTION or MIX COOK; “H” level otherwise.

-lgifFz.wi:: GND ON

38 R5

39 R6

OUT Damper motor relay driving signal.

To turn on and off the shut-off relay (RY6).

OFF H

-_------L ON

OUT Terminal not used.

40 R7

41 E37

IN

IN

Input signal which communicates the damper open/close information to LSI.

Damper opened; “H” level signal (0V:GND) Damper closed; “L” level signal (- 5V:VC)

Terminal not used. Connected to VC.

42 E36

43 AVSS

44 AVR-

IN

IN

IN

Input signal which communicates the door open/close information to LSI.

Door closed; “H” level signal (OV). Door opened; “L” level signal (-5V)

Connected to VC.

Reference voltage input terminal.

A reference voltage applied to the A/D converter in the LSI. The reference voltage is generally maintained at -5V.

45 AVR + IN Reference voltage input terminal.

A reference voltage applied to the A/D converter in the LS I. Connected to GND. (OV)

46 AVCC IN Connected to GND.

25

R-8270

I/O

IN

Description

Signal coming from touch-key.

When either one of G-l 1 line keys on key matrix is touched, a corresponding signal oul

of E7, El 1 -El 3 and El 5 will be input into AN7.

When no key is touched, the signal is held at “L” level.

IN Signal similar to AN7.

When either one of G-10 line keys on key matrix is touched, a corresponding signal wil

be input into AN6.


When either one of G-9 line keys on key matrix is touched, a corresponding signal will

be input into AN5.

1 Pin No. Signal

1 I 47 1 AN7

I

,,t


When either one of G-8 line keys on key matrix is touched, a corresponding signal will

be input into AN4.

Terminal not used. IN

IN

Temperature measurement input: OVEN THERMISTOR.

By inputting DC voltage corresponding to the temperature detected by the thermistor,

this input is converted into temperature by the A/D converter which is built into the

LS I.



Terminal not used.

IN

IN

53 AN1

OUT

OUT 56 R9

OUT

OUT

57 RIO

58 RI1

59 RI2 OUT

Terminal not used.


OUT

OUT

62 RI5 IN Terminal for manufacture test.

Normally, connected to VC (--5V)

G-l--& Terminal not used. Connected to GND.

Connected to GND.

NC

IN

i

26

R-8270

POWER SOURCE CIRCUIT

240 V AC power is applied to the primary winding of trans-

former (Tl ). The output voltage of the secondary winding of

transformer (Tl ) is then full-wave rectified by the diode bridge

and smoothed by the electrolytic capacitor to become DC vol-

tage VI.

Then the voltage VI is delivered to the constant voltage

circuit.

Another output, S2 of power transformer Tl is half-wave rec- VP -34v Fluorescent UI>C)ICI~

: Grid and anode vo tified to power the filament of fluorescent display tube or rec-

tified in negative voltage to drive the grid and anode of

fluorescent display tube.

I VFl -7!iv Filap,-.-+ A& $1, ~ern.-am . / -- ..-jll=Ill oI IluvlGP~ent display

VF2 j -28V tube: VFI - VF2 voltage.

7 GND

To Relay Contact To Synchronlzing Slpnal Clrcult

To Relay Circuit To Buzzer Circuit

Figure T-3.

SYNCHRONIZING SIGNAL CIRCUIT

The secondary winding output voltage of the transformer (Tl ) This is the basic timing for all time processing.

is half wave rectified, subjected to a voltage division by R21 C20: Noise filter capacitor.

and R23 and treated as a power source synchronizing signal. D20: Clamp diode.

R** 31 +‘A-- IRO E27

Figure T-4.

27

R-8270

ACL CIRCUIT

By switching on power, charge current (iI) is fed to C30

through R30 and generates Vz voltage.

If Vz exceeds the threshold voltage of ZD30, 2030 is turned

on and the current iz flows. Thus, placing voltage on to the base

of transistor Q30 and turning it on.

A reset signal is obtained from the collector.

C31: Noise filter capacitor.

Figure T-5.

RESET

BUZZER CIRCUIT

This circuit is an oscillation circuit which is composed of piezo- LSI (IC 1) produces three types of alarm sound by emitting the

electric buzzer SP40 with feedback electrode and transistor 040. signal to control Q41 as illustrated.

Q41 works to switch on the buzzer circit and controls how

long the alarm continues to sound.

‘2Lz---r 45L---: 041 i:i:j’, r---- -1

c-n=u-Lr:

30 EX

L ---- J LSi

IC 1

Figure T-6.

THERMISTOR SENSOR CIRCUIT

LSI has a built-in A/D converter.

Analog DC voltage input to AN 1 terminal is digitally convert-

ed into temperature data.

The thermistor sensor circuit is basically constituted by the

potential division circuit for R67 and THERMISTOR against the

standard voltage of VC.

Accordingly, the temperature detected by THERMISTOR is in-

put to AN 1 input terminal of LSI as analog DC voltage value.

Figure T-7.

28

R-8270

RELAY CIRCUIT

The output available at the secondary side of the transformer

is rectified by the diode bridge (D 1 -D4) to procedure a pow-

er of VL and this power is used to activate the relay circuit.

The pulse signal goes out of pin 34 (RI ) of LSI and it is recti-

fied by 080 and D81 to have the capacitor C81 charged. With

C81 charged up the potential at the base of Q82 becomes.

Low level so that Q82 turn on. The transistors Q81 and 084

are designed to turn on when the signals at pins 33 (RO) and

35 (R2) of LSI are both at Low level. The transistors 082 and

Q81 (or 084) are connected in series with each other, and the

relays RYI (or RY4) are allowed to turn on only when both

trnsistors turn on simultaneously.

The relays RY3, RY5 and RY6 are designed to turn on when

the signals at pins 36 (R3), 37 (R4) and 38 (R5) of LSI are all

at Low level.

At the same time when Q84 is turned on, RY3 is activated

by D84.

Figure T-8.

INDICATOR CIRCUIT

Method of Display

Indicator element is Fluorescent Display.

Basically, a Fluorescent Display is a triode having a cathode,

a grid and an anode. Usually, the cathode of Fluorescent Dis-

play is directly heated and the filament serves as cathode.

When a proper voltage is applied to the filament to heat it,

thermo-electrons are emitted and, with positive voltage with

respect to filament being applied to the anode and grid, elec-

trons hit against the anode to illuminate the fluorescent body.

If the anode or grid voltage is zero or negative against the fila- Jr ment, thermo-electrons can not reach the anode, hence the

fluorescent body is not luminescent.

In this model, the Fluorescent Display 6-digits, 13 segments

are used for displaying figures.

The Fluorescent Display employs the dynamic drive method,

when the high level of anode signal and grid signal agree, the

corresponding segment displays.

The following signals are responsible specifying segments.

4

E6,E7 and ES- El9 lo-K,VB and LB1

- T I

EO- E5 64

0 IlG - 6G) ---

VCC --T-

I ml0 I 0

VP L-VI4

LSI c VF2 Fi I omenr

Figure T-9.

Segment 1 Signal 1 Segment 1 Signal

Character format

Indi- cator

29

R-8270

SERVICING

1. Precautions for Handing Electronic Components

This unit uses PMOS LSI in the integral part of the circuits.

When handing these parts, the following precautions

should be strictly followed.

PMOS LSI have extremely high impedance at its input and

output terminals. For tis reason, it is easily influenced by

the surrounding high voltage power source, static elec-

tricity charged in clothes, etc. and sometimes it is not fully

protected by the built-in protection circuit.

In order to protect PMOS LSI.

1)

2)

When storing and transporting, throughly wrap them

in aluminum foil.

Also wrap PW boards containing them in aluminium

foil.

When soldering, ground the technician as shown in

the figure and use grounded soldering iron and work

table.

. .

/

-orox IMR

h

2. Shapes of Electronic Components

Transistor

Transistor DTA143EA, 2SA937 2SA885A 2SB910,2SC2021

3. Servicing of Touch Control Panel

We describe the procedures to permit servicing the touch

control panel of the microwave oven and the cautions you

must consider when doing so.

To carry the servicing, power supply to the touch control

panel is available either from the power line of the oven

proper itself of from an external power source.

(I ) Servicing the touch control panel with power supply

from the oven proper:

CAUTION:

THE HIGH VOLTAGE TRANSFORMER OF THE

MICROWAVE OVEN IS STILL ALIVE TO GIVE YOU

DANGER DURING SERVICING.

Therefore, when checking the performance of the

touch control panel, put the outer cabinet on the oven

proper to keep you from touching the high voltage

transformer, or unplug the primary terminal (connec-

tor) of the high voltage transformer to turn it off; and

the end of such connector shall be insulated with an

insulating tape. After servicing, be sure to replace the

leads to their original locations.

A. On some models, the power supply cord between the

touch control panel and the oven proper is so short

that they can’t be separated from each other.

For those models, therefore, check and repair all the

controls (with the sensor-related ones included) of the

touch control panel while keeping it in contact with

the oven proper.

B. On some models, on the other hand, the power sup-

ply cord between the touch control panel and the oven

proper is so long that they may be separated from each

other. For those models, therefore, it is allowed to

check and repair the controls of the touch control

panel while keeping it apart from the oven proper; in

this case you must short both ends of the stop switch

(on PWB) of the touch control panel with a jumper,

which brings about an operational state that is equiva-

lent to that with the oven door being closed.

As to the sensor-related controls of the touch control

panel, their checking is allowed if the dummy resis-

tor(s) whose resistance is equal to that of those con-

trols is used.

(2) Servicing the touch control panel with power supply

from an external power source:

Disconnect the touch control panel completely from

the oven proper, and short both ends of the stop

switch (on PWB) of the touch control panel, which

brings about such an operational state that is equiva-

lent to that with the oven door being closed. And con-

nect an external power source to the power input

terminal of the touch control panel, and then it is al-

lowed to check and repair the controls of the touch

control panel; as in the case of (1 )-B above, it is here

also possible to check the sensor-related controls of

the touch control panel by using the dummy

resistor(s).

4. Sevicing Tools

Tools required when servicing the touch control panel as-

sembly.

1) Soldering: 30W

(To prevent leaking current, it is recommended to use

a soldering iron with grounding terminal.)

’ 2) Oscilloscope: Single beam, frequency range: DC -

IOMHz type or more advanced model

3) Others: Other tools

5. Other Precautions

1)

2)

3)

4)

5)

When turning on the power source of the control unit,

remove the aluminum foil applied for preventing stat-

ic electricity.

Connect the connectors of the indicator and key units

to the control unit taking care that the lead wires are

not twisted.

After aluminum foil is removed, take extra care that

abnormal voltage due to static electricity etc. is not

applied to the input or output terminals.

Attach connectors, electrolytic capacitors, etc. to PW

board, taking care that all connections are tight.

Be sure to use specified components where high pre-

cision is required.

30

R-8270

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

WARNING: to avoid possible exposure to microwave energy;

A. Before operating the oven;

1. Make sure that unlatching the door slowly is accom-

panied by a click indicating actuation of the latch

switches.

2. Check visually the door seal for arcing and/or damage.

B. Do not operate the oven until after repair if any of the fol-

lowing conditions exist;

1. Door does not close firmly.

2. There is a broken door hinge or support.

3. The door gasket or seal is damaged.

4. The door is bent or warped.

5. There is any defective parts in the interlock, oven door

or microwave generating and transmission assembly.

6. There is any other visible damage to the oven.

C. Do not operate the oven;

1. Without the RF gasket.

2. If the waveguide and oven cavity are not intact.

3. If the door is not closed.

CAUTION: WHEN THE OUTER CASE IS REMOVALED, DIS-

CHARGE THE HIGH VOLTAGE CAPACITOR BE-

FORE TOUCHING ANY OVEN COMPONENTS OR

WIRING.

HIGH VOLTAGE COMPONENTS REMOVAL (High Voltage Capacitor and Rectifier)

To remove the components, proceed as follows.

1. Disconnect the oven from the power supply and remove

the outer case.

2. Discharge the high voltage capacitor.

3. Disconnect the wire leads from the high voltage capacitor.

4. Remove the single (1) screw holding the capacitor holder

to the mounting bracket, and remove the capacitor holder.

5. Remove the single (I) screw holding the earth side termi-

nal of rectifier.

6. Now, the capacitor and rectifier are free.

CAUTION: WHEN REPLACING THE RECTIFIER, THE EARTH

SIDE TERMINAL MUST BE SECURED FIRMLY

WITH A EARTHING SCREW.

POWER TRANSFORMER REMOVEL

1. Disconnect the oven from the power supply and remove

the outer case.


3. Disconnect the wire leads from the power transformer.

4. Disconnect the filament leads from the magnetron and

high voltage capacitor.

5. Remove the two (2) screws holding the transformer to the

base cabinet.

6. Remove the transformer.

SILICON RECTIFIER REMOVAL

1. Disconnect oven from power supply and remove outer 4. Disconnect the rectifier from the capacitor.

case.


3. Remove the one (1) screw holding the rectifier to the fan

duct assembly.

CAUTION: WHEN REPLACING THE SILICON RECTIFIER, THE

GROUND SIDE TERMINAL MUST BE SECURED

FIRMLY WITH A GROUNDING SCREW.

Figure C-l. Cabinet Parts

R-8270

1.

2.

3.

1.

2.

3.

4.

1.

2.

3.

4.

5.

1.

2.

3.

4.

HIGH VOLTAGE CAPACITOR REMOVAL

Disconnect oven from power supply and remove Outer 4. Remove the one (I) screw holding the capacitor holder

case. to the fan duct assembly.

Discharge the high voltage capacitor. 5. Remove the capacitor holder with capacitor.

Disconnect the wire leads and rectifier from the Capacitor. 6. Remove the capacitor from the holder.

TURNTABLE COUPLING REMOVAL

Open the door and remove the turntable and turntable

roller assembly.

Remove the turntable motor.

Remove the these (3) screws holding the turntable motor

mounting plate to the bottom oven cavity.

Remove the coupling stopper ring (CS-ring) and the

coupling spacer from the coupling.

MAGNETRON ASSEMBLY REMOVAL

T-

TURNTABLE COUPLING

er ~Z’,“,“,V,TY

r-qz+--.y

Figure C-2. Cabinet Parts

Disconnect oven from power supply and remove outer

case.

Discharge the high voltage capacitor.

Disconnect the wire leads from the magnetron asembly.

Remove one (1) screw holding the magnetron air guide

to the magnetron, and remove the magnetron air guide.

Carefully remove the four (4) mounting screws holding the

magnetron to the waveguide while supporting the magne-

tron from below.

6. Lower the magnetron until the tube is clear of the

waveguide.

CAUTION: WHEN REPLACING THE MAGNETRON, BE

SURE THE R.F. GASKET IS IN PLACE AND THE

MAGNETRON MOUNTING SCREWS ARE

TIGHTENED SECURELY.

DAMPER MOTOR ASSEMBLY REMOVAL (Damper motor and Damper switch)

Disconnect oven from power supply and remove outer 2. Remove the two (2) screws holding the damper motor to

case. the damper motor assembly.

Discharge the high voltage capacitor. 3. Remove the damper motor.

Remove the magnetron assembly, refer to “MAGNETRON DAMPER SWITCH ASSEMBLY REMOVAL”. 1. Disconnect the wire leads from the damper switch. Remove the two (2) screws holding the damper motor as- 2. Remove one (1) screw holding the damper switch to the sembly to the oven cavity and remove the damper motor damper motor assembly. assembly. 3. Remove the damper switch.

DAMPER MOTOR

1. Disconnect the wire leads from the damper motor.

Figure C -2. Oven Parts

32

HEATER OR CONVECTION FAN REMOVAL

1. Disconnect the oven from power supply and remove the HEATING ELEMENT

outer case. 1. Remove the heater insulator (6).

2. Discharge the high voltage capacitor. 2. Remove the two (2) screws holding the heater insulator

3. Disconnect the wire leads from the seath heater. (A).

4. Remove the two (2) screws holding the pully cover, and 3. Remove the heating element.

remove it. CONVECTION FAN 5. Remove the convection belt. 1. Remove the nut. 6. Remove the five (5) screws holding the rear cabinet. 2. Pull the fan from the fan shaft. 7. Remove the ten (10) screws holding the convection fan

duct.

THERMISTOR REMOVAL

1. Remove the pully cover, and the rear cabinet, refer to 3. Remove the two (2) screws holding the thermistor to the

“HEATER OR CONVECTON FAN REMOVAL”. convection fan duct.

2. Disconnect the wire leads from the thermistor. 4. Remove the thermistor from convection fan duct.

CONTROL PANEL ASSEMBLY REMOVAL

To remove the control panel, proceed as follow: 5. Remove one (1) screw holding the control panel back plate

1. Disconnect oven from power supply and remove outer to the chassis support.

case. 6. Remove two (2) screws holding the bottom edge of the

2. Discharge the high voltage capacitor. back plate to the unit chassis.

3. Disconnect a connector from the control unit. 7. Remove two (2) screws holding the back plate to the oven

4. Remove two (2) screws holding the relay unit to the con- cavity flange.

trol panel back plate and separate the relay unit from the 8. Lift up and pully the control panel forward.

control unit.

LATCH SWITCH

DISPLAY FILTER

KEY UNIT ANGLE

ONTROL PANEL

Figure C-3. Control Panel Parts

33

R-8270

LATCH SWITCHES, STOP SWITCH AND MONITOR SWITCH REMOVAL

I, Disconnect oven from power supply and remove outer case


3. Disconnect the wire leads from the switches.

4. Remove one (1) screw holding the upper latch hook to the

control panel back plate and remove one (1) screw hold-

ing the lower latch hook to the control panel back plate.

5. Remove the latch hookes from the control panel back plate

by moving it downward.

6. To remove the individual switch from the latch hookes,

push outward on the two (2) retaining tabs holding the

switch in place.

Re-install

1. Re-install the individual switch to the upper latch hook and

lower latch hook, refer to Figure C-4.

2. Re-connect the wire leads to the individual switch, refer-

ring to pictorial diagram.

3. Secure the individual latch hook with the one (1) mount-

ing screw to the conrol panel back plate.

4. Make sure that the monitor switch is operating properly,

refer to Test Procedure.

UPPER AND LOWER LATCH SWITCHES AND

MONITOR SWITCH ADJUSTMENT

lf the primary and secondary interlock switches and monitor

switch do not operate properly due to mis-adjustment, the

following adjustment should be made.

1. Loosen the screw holding the upper latch hook to the con-

trol panel back plate.

2. With the door closed, adjust the lower latch hook by

moving it back and forth and then adjust the upper latch

hook by moving it back and forth, or up and down.

In and out play of the door allowed by the upper and lower

latch hooks should be less than 0.5mm.

The vertical position of the upper latch hook should be set

where the primary interlock switch and monitor switch

have activated with the door closed.

Vertical adjustment of the lower latch hook is not possible.

3. Secure the screws with washers firmly.

4. Now, make sure of the primary interlock switch operation.

If the primary interlock switch has not activated with the

door closed, loosen the one (1) screw holding the upper

latch hook to the control panel back plate and adjust the

upper latch hook position.

After the adjustment, make sure of the following points:

1. The in and out play of the door remains than 0.5mm at

latched position. First check the uper latch hook position,

pushing and pulling the upper portion of door toward the

oven face. Then check the lower latch hook position, push-

ing and pulling the lower portion of door toward the oven

face. Both results (plays of the door) should be less than

0.5mm.

2. The primary and secondary interlock switches intrrupt the

circuit before the door is opened.

The monitor switch contacts close when the door is

opened.

3. Re-install the outer case and check for microwave leakage around the door with an approved microwave survey meter.

(Refer to Microwave Measurement Procedure.)

UPPER LATCH HEAD

..-.- /

OPEN BUTTON

Figure C-4. Latch Switches Adjustment

34

DOOR REPLACEMENT AND ADJUSTMENT

DOOR REPLACEMENT

1.

2.

3.

4.

5.

6.

7.

Disconnect the oven from the power supply and remove

the outer case.

Discharge the high voltage capacitor.

Remove the five (5) screws holding the upper and lower

oven hinge to the oven cavity. The lower oven hinge is

now free.

Remove the door assembly with upper oven hinge by pull-

ing it forward.

Separeate the door assembly and upper oven hinge. The

door assembly is now free.

Re-installing the upper oven hinge to the new door as-

sembly.

On re-installing the new door assembly, secure the door

assembly with the five (5) mounting screws to the oven

cavity.

Make sure the door is parallel with bottom line of the oven

face plate and the latch head pass through the latch holes

correctly.

Note: After any service to the door, and approved micro-

wave survey meter should be used to assure in com-

pliance with proper microwave radiation stadards.

(Refer to Microwave Measurement Procedure.)

DOOR ADJUSTMENT

When removing and/or loosening hinge such as in the case of

a door replacement, the following adjustment criteria are taken.

Door is adjusted to meet the following three conditions by

keeping screws of hinge loose.

1.

2.

3.

4.

Adjust door latch head at a position where they smoothly

catch the latch hook through the latch hole. Refer to latch

switch adjustment.

Deviation of the door alignment from the horizontal line

of the cavity face plate is to be less than 1 .Omm.

The door is positioned with its face depressed toward the

cavity face plate.

Reinstall the outer case and check the microwave leak-

age around the door with an approved microwave survey

meter. (Refer to Microwave Measurement Procedure.)

Door Component Removal

(I 1 Insert a thin bladed screwdriver to the square holes at the

lower side of the door frame to unlock the tabs of the

choke cover.

(2) Checking that the tabs at the right and left sides of the

choke cover are also unlocked,

while holding it up.

~:I~

Door Inside

(3)

(4)

Remove the screws (A).

Hold up the latch cover until its lower tabs are removed,

then detach the latch cover.

Inside

Figure C-7

(5) Remove the screw (B) retaining the latch assembly, and

detach the latch assembly while pulling it frontward.

(6) Release the latch springs and remove the latch levers.

Keep the door glass and

door frame as they are

without removing them. I

remove the choke cover

Door Outside

Figure C-6

SCREW ,B,

Figure C-5 Door Assembly Replacement and Adjustment

Figure C-8

35

MICROWAVE MEASUREMENT

After the adjustment of the latch switches and door is com- Recommended instruments are:

pleted individually or collectively, the following leakage test NARDA 8100

must be performed with a survey instrument and it must be NARDA 8200

confirmed that the result meets the requirements of the per- HOLADAY HI 1500

formance standard for microwave oven. SIMPSON 380M

REQUIREMENT 2.

3.

The safety switch must prevent microwave radiation emission

in excess of 5mW/cmz at any point 5cm or more from exter-

nal surface of the oven.

PREPARATION FOR THE TESTING: Before beginning the actual test for leakage, proceed as follow;

1. Make sure that test instrument is operating normally as

specified in its instruction booklet.

Important:

Survey instruments that comply with the requirement for

instrumentation as prescribed by the performance stan-

dard for microwave ovens must be for testing.

4.

Place the turntable tray into the oven cavity.

Place the load of 275 + 15 ml of water initially at

20+5OC in the centre of the oven tray. The water con-

tainer should be a low form of 600ml beaker with inside

diameter of approx. 8.5cm and made of an electically non-

conductive material such as glass or plastic.

The placing of this standard load in the oven is important

not only to protect the oven, but also to insure that any

leakage is measured accurately.

Close the door and turn the oven ON with the timer set

for several minutes. If the water begins to boil before the

survey is completed, replace it with 275ml of the cool

water.

5. Move the probe slowly (not faster that 2.5cmisec.) along

the gap.

The microwave radiation emission should be measured at

any point of 5cm or more from the external surface of the

oven.

6.

36

R-8270

1 I 2 3 I 4 I 5 r I 6

1 I 2 I 3 I 4 I 6 I 4

A

B

C

D

E

F

~

G

I

H

37

R-8270

1 I 2 I 3 I 4 I 5 1 a

1 I 2 I 3 I 4 I 6 I 6

1

A

B

C

D

E

f

G

H

A

R-8270

1 I 2 j 3 I 4 I 5 ! 6

, I&F,

_

_ -

--!I- l �. = m ,+

-5- romr~ u4, ______a _.- -.

l 8 . -l-l

IYIYJI.I. It,

LT toloz,~ to rololl~ MN1 P t01001~ l?!,

II 3 ::

32 - m ?I -

: = 3 e Y I g

‘n /!I

.z I “x s F I ;- F -; n,>

;..*.=.. I I

-. - ;I’ -Lg[;;

-~.: .; &j-+-+$$ :;,“; .:

-

Note: Symbols R30 and R31 are incorrect on PWB No. A

WRONG CORRECT

R30 + R31

R31 --i R30

These symbols are corrected after PWB No. L& .

Control Unit Relay Unit

Figure S-3. Printed Wiring Board on Parts Position Side.

1 I 2 I 3 I 4 I 5 I 6

39

R-8270

PARTS LIST

REF.NO. PART NO. DESCRIPTION Q’TY CODE

l- 1

l- 2

I- 3

l- 4

l- 5

l- 6

l- 7

l- 8

l- 9

I-10

l-1 1

l-12

l-13

l-14

1-15

1-16

1-17

l-18

l-19

l-20

1-21

2- 1 LANGQA030WRWO Electric parts mounting bracket

2- 2 TLABS0057WRRO Fuse label

2- 3 FDUC-AOISWRWO Fan duct assembly

2- 4 FFANJ0031WRKO Fan blade

2- 4A LSTY-0030WREO Fan retainer clip

2- 5 LBNDK0035WRPO Capacitor holder

2- 6 GDA i-A01 SWRWO Unit chassis

2- 7 GLEGPAOOSWREO Foot

2- 8 LANGFA014WRPO Chassis support

2- 9 PCUSU0326WRPO Shading cushion

2-10 LSTPP0008YBFO Cord anchorage (upper)

2-l 1 LSTPP0009YBFO Cord anchorage (lower)

2-12 NPLYB0031WRFO Motor pully

2-13 GCABUA053WRPO Outer case cabinet

2-14 TMAPCAlSOWRRO Schematic diagram

Note: THE VOLTAGE SUPPLIED TO THE PARTS MARKED “t” IS GREATER THAN 250V.

40

ELECTRICAL PARTS

3 SW-M 0 1 7 2 W R E 0 Monitor switch (V-l 6G-2C25)

1 SW-M 0 1 7 3 W R E 0 ’ Upper latch switch (V-l 6G-3C25)

Q SW-M 0 1 7 4 W R E 0 Stop switch and damper switch (V5330DK)

Q SW-M 0 1 7 1 W R E 0 #Lower latch switch (V-l 6G-1 C25)

R T R N - A 0 1 0 D R E 0 Transformer for control unit

R H - D Z A 0 0 2 W R E 0 Short protecter

QFSHDOOl SWREO Fuseholder

F H-HZ 0 0 2 4WR E 0 Thermister

R C-Q Z A 0 0 9 W R E 0 High voltage capacitor

RH-DZAOOlWREO Rectifier

RLMPT0038WREO Ovenlamp

RMQTEAOl 5WRE0 Fanmotor

RTRN-AO33WREO Powertransformer

QACCA0032WREO Mainsupplycord

QFS-T0026WREO Temp.fuse

RMQTEAOl 4WRE0 Convectionfanmotor

RMQTDAOl 8WRE0 Dampermotor

RHET-A005WREO Heater

R M 0 T D 0 0 8 1 W R E 0 Turntable motor

RV-MZA008WREO Magnetron - QFS-CO01 SWREO FuseM6.3A

CABINET PARTS

1

1

2

1

1

1

1

1

1

1

2

1

1

1

1

I

1

1

1

1

1

AG

AG

AH

AG

AW

AQ

AF

AQ

AY

AM

AH

AW

BP

AR

AG

AW

AS

AY

AT

BL

AE

AG

AA

AP

AF

AA

AB

AR

AB

AE

AB

AC

AC

AC

BA

AD

R-8270

PARTS LIST

REF.NO. PART NO. DESCRliTlON Q’TY CODE

2-15 PCUSGA023WRPO Cabinetcushion 2 AA

2-16 PCUSU031 5WRPO Fanductcushion 1 AA

CONTROL PANEL PARTS

t

*

3- 1 C P W B F 2 1 2 SW R K 0 Control unit 1 BT

3- 1A Q C N C M A 0 1 3 D R E 0 13-pin connector (D) 1 AD

3- IB Q C N C M A 0 4 0 D R E 0 6-pin connector (E) 1 AC

3- 1c QCNCWA030DREO 12-pinconnector 1 AE

3- 1D Q C N C M A 0 4 7 D R E 0 2-pin connector (H) 1 AB

3- 1E R V-K X A 0 0 3 D R E 0 Fluorescent display tube 1 AX

C3, C6 RC-EZA059DREO Capacitor 1Op.F 25v 2 AB

c4 RC-EZAOG 1 DREO Capacitor 4.7pF 5ov 1 AB

c5, c7 RC-KZA004DREO Capacitor 0.015pF 25V 7 AA

c20, c31

C65, C70

c75

c9 RC-EZA057DREO Capacitor 1 OOpF 16V 1 AB

Cl0 RC-EZA058DREO Capacitor 22/~F 25V 1 AB

C30 RC-EZAOGODREO Capacitor 47pF 16V 1 AB

C80 RC-EZAO63DREO Capacitor 0.47/~F 5ov 1 AA

C81 RC-EZA062DREO Capacitor 3.3/~F 5ov 1 AA

3Fl R C R S-A 0 0 3 D R E 0 Ceramic filter (4.0 MHz) 1 AF

17, D20 RH-DZA002DREO Diode(US1060) 13 AA

D80-D83

D91-D97

18, D9 RH-DZAO 11 DREO Diode(llE1) 2 AB

Cl RH-i X2429DREO LSI 1 AV

31 R H - T Z A 0 0 8 D R E 0 Transistor (2SA885Q, R) 1 AE

230, Q41 R H-T Z A 0 2 2 D R E 0 Transistor (DTAI 43EA) 7 AB

Q81,

Q83-Q86

180 R H-T Z A 0 2 5 D R E 0 Transistor (2SC2021M [Q], [RI, [S]) 1 AB

382 R H-T Z A 0 2 1 D R E 0 Transistor (2SB91OM [RI) 1 AC

31 R R - D Z 3 3 1. N D R E 0 Resistor 3300 114w 1 AA

32 RR-DZ 15 1 PDREO Resistor 1500 112w 1 AA

33 RR-DZ 12 1 PDREO Resistor 12ofi 112w 1 AA

34 RR-DZ27 1 PDREO Resistor 27Ofi 112w 1 AA

322, R82 R R-D Z 4 7 3 N D R E 0 Resistor 47kfl 114w 4 AA

R201,

R203

*: See page 47.

41

R-8270

PARTS LIST

I I REF.NO. PART NO. DESCRIPTION Q’TY CODE

~23, R31 R R-D Z 1 5 3 N D R E 0 Resistor 15kn 114w 2 AA

R30 RR-DZ47 1 NDREO Resistor 47ofl 114w 1 AA

R50 R R-D Z A 0 0 5 D R E 0 Resistor block (RNAFST) 11 AD

R66, R71 RR-DZ 102NDREO Resistor Ikfi 114w 4 AA

R76. R80

R67 RR-NZ752NDREO Resistor 7.5kfl(F) 114w 1 AA

R70, R75 R R-D Z 2 7 3 N D R E 0 Resistor 27kfI 114w 2 AA

R81 RR-DZl 03NDRE0 Resistor 1 Okn 1 l4W 12 AA

R91-R97

Rl OO-

R103

R83 RR-DZ472NDREO Resistor 4.7k&’ 114w 1 AA

R84 RR-DZ222NDREO Resistor 2.2k!-l 114w 1 AA

R90 R R-D Z A 0 2 9 D R E 0 Resistor block (1OOkfi x 4) 1 AB

RllO R R-D Z A 0 2 7 D R E 0 Resistor block (27kB x 6) 1 AC

RI11 RR-DZA030DREO Resistorblock(56kfixl5) 1 AD

R200 RR-DZ204NDREO Resistor 200kQ 1/4w 1 AA

ZDl RH-EZA050DREO Zenerdiode(RD16EB3) I AB

ZD2 RH-EZA05 1 DREO Zenerdiode(RD5.fEB3) 1 AB

ZD30 R H- E Z A 0 5 2 D R E 0 Zener diode (RD3.6EL2) 1 AB

3- 2 FPWBFAl 04WRE0 Relayunit 1 BH

3- 2A Q P L G J 2 3 9 6 Y A Z Z 7-pin connector (A) 1 AD

3- 2B Q C N C M 2 3 9 0 Y A Z Z 4-pin wire connector (B) 1 AM

3- 2c Q C N C M 2 4 1 0 Y A Z Z 13-pin wire connector (C) 1 AD

3- 2D Q P L G J 2 3 9 7 Y A Z Z 8-pin connector (I) 1 AC

3- 2E Q F S H A 2 0 0 2 Y A Z Z Fuse holder 2 AA

Cl VC Q Y C U 1 H M 1 0 4 K Capacitor 0.1 PF 5ov 1 AB

c2 VCEAAH 1 VW1 08M Capacitor 1 OOOpF 35v 1 AE

C8 V C T Y P U 1 E F 1 0 4 Z Capacitor O.lpF 25V 1 AA

Cl 80 VCEAAUl HWI 06M Capacitor 1 OpF 5ov 1 AB

Dl-D5 VHDl lE1 / / ii-1 Diode(llE1) 5 AB

D84. VHDUSI 060 / !--I Diode(US1060) 7 AA Dl81-

D186

Fl QFS-A2042YAZZ Fuse 1 AC

Ll R C i L F 2 0 0 3 Y A Z Z Filter coil (22pH) 1 AC

Q40 VS2SA937Q/i--1 Transistor (2SA937Q) 1 AB

R20 VRD-ST2EFl 83J Resistor 18kfl 1 i4W

R21,R42 VRD-ST2EFl 03J Resistor 1 OkR 1 i4W ’ I ;,” 2

R40 VRD-ST2EFl 54J Resistor 150kR 1!4W 1 AA

R41 VRD-ST2EF47 1 J Resistor 470R 114w 1 AA

RYl-RY6 R R L Y- 2 1 1 8 Y A Z Z Relay (D.C. 14V) 6 AN

*: See page 47 42

R-8270

PARTS LIST

REF.NO. PART NO. DESCRIPTION Q’TY CODE I

SP40 RALM-2021 YAZZ Buzzer 1 AF

VRSl RH-VX201 SYAZZ Varistor 1 AF

3- 3 JBTN-Al 6lWRFO Openbutton 1 AD

3- 4 MSPRC0066WREO Buttonspring 2 AA

3- 5 LANGKAO69WRFO Upperlatchhook 1 AE

3- 6 LANGKA083WRFO Lowerlatchhook 1 AF

3- 7 L A N G T A 0 4 0 W R W 0 Control panel back plate 1 AK

3- 8 MLEVFAOI OWRWO Openlever 1 AD

3- 9 M L E V F 0 1 2 4 W R E 0 Monitor switch lever 1 AC

3-10 MLEVP0099WRFO Switchlever 1 AC

3-11 MSPRTOI OIWREO Openleverspring 1 AA

3-12 HPNLCAI 48WRF0 Controlpanelframe 1 AN

3-13 DUNTKA084WREO Keyunit 1 AY

3-14 LANGTA044WRWO Keyunitangle 1 AH

3-15 G M A D i A 0 2 8 W R R 0 Display filter 1 AG

3-I 6 PCUS-A035WRPO Cushion(T5x22x22) 1 AB

OVEN PARTS

4- 1 F R 0 L P A 0 0 7 W R K 0 Turntable roller assembly 1 AP

4- 1A N R Q L P A 0 0 7 W R E 0 Turntable roller 3 AE

4- 1B X W H T Z 4 1 - 1 0 1 0 0 Washer turntable roller mtg ; 3 AA

4- 1c X R S U W 3 0 - 2 5 0 0 0 Ring turntable roller mtg ; 3 AA

4- 2 NTNT-AOOSWRHO Turntabletray 1 AU

4- 3 FBRG-A00 1 WREO Bearing 1 AM

4- 4 FDUC-A024WRYO Convectionfanduct 1 AW

4- 5 FFANMAOOIWRYO Convectionfan 1 AG

4- 6 L A N G T A 0 2 3 W R W 0 Bearing mounting bracket 1 AE

4- 7 L A N G T A 0 2 4 W R P 0 Bearing fixing plate 1 AC

4- 8 NPLYBA004WRFO Convectionfanpully 1 AD

4- 9 P G i S H A 0 0 4 W R E 0 Convection heater insulator (A) 2 AF

4-10 P G i S H A 0 0 5 W R E 0 Convection heater insulator (B) 2 AC

4-11 DQVN-A040WRYO Ovencavity 1 BP

4-12 PCQVPA027WREO Waveguidecover 1 AE

4-13 NSFTTAOI 7WRM0 Dampershaft 1 AA

4-14 PCUSU041 SWRPO Dampercushion 1 AA

4-15 PDUC-A06 1 WRWO Airduct 1 AK

4-16 PFTA-AOOSWRWO Dampercover 1 AD

4-17 P S L D H A 0 1 1 W R W 0 Thermal protection cover 1 AP

4-18 GCABDAO 1 OWRWO Rearcabinet 1 AQ

4-19 GDA i-A0 18WRPO Basecabinet 1 AQ

43

R-8270

PARTS LIST

REF.NO. PART NO. DESCRIPTION Q’TY CODL 1

4-20 GLEGPA003WREO Foot

4-21 LANGQA026WRPO Turntable motor mounting plate

4-22 LFiX-AOOGWRFO Oven lamp glass flange

4-23 LHLDK0005YBFO Cord holder

4-24 NCPL-AOIOWRFO Turntable coupling

4-25 PCUSUA028WRPO Air guide cushion

4-26 FDUC-A027WRYO Steam duct

4-27 PFPF-A004WREO Thermal protection sheet (rear)

4-28 PFPF-A005WREO Thermal protection sheet (right)

4-29 PGLSPA030WREO Oven lamp glass

4-30 PSKR-AO23WRPO Partition plate

4-31 PSKR-A01 8WRP0 Magnetron air guide

4-32 FCOVHAOOSWRWO Pully cover

4-33 FHNG-0102WRYO Upper oven hinge

4-34 FHNG-01 03WRY0 Lower oven hinge

4-35 GCOVHA027WRPO Turntable motor cover

4-36 NBLTKA002WREO Convection belt

4-37 MCAMPA008WRFO Damper cam

4-38 PCUSU0309WRPO Magnetron air guide cushion (A)

4-39 PSPAGAOIOWRPO Turntable motor spacer

4-40 PCUSU0296WRPO Thermal protection cover cushion

4-41 PCUSU0158YBPO Supporting cushion

4-42 PZETEA008WRPO High voltage insulator

4-43 PCUSUA044WRPO Magnetron air guide cushion (B)

DOOR PARTS

5 C D 0 R F A 0 8 2 W R K 0 Door assembly, complete

5- 1 F A N G K A 0 2 2 W R Y 0 Latch plate

5- 2 LSTPP0067WRFO

5- 3 LSTPP0068WRFO

5- 4 M L E V F 0 2 8 8 W R P 0 Joint lever

5- 5 MLEVP0095WRFO Doorlever

Upper latch head

Lower latch head

5- 6 MSPRT0059WREO Latch spring

5- 7 DDORFA050WRYO Door panel

5- 8 GCoVAA052WRFO Latch cover

5- 9 GWAKPAOlOWRRO Door frame

5-10

5-l 1

5-12

PGLSPA044WREO Outside door glass

GCCVHA041WRFO Choke, cover

P C U S G A 0 6 6 W R P 0 Water-proof cushion

I AB

AF

AK

AB

AK

AC

AM

AH

AG

AG

AD

AE

AN

AE

AE

AB

AD

AD

AA

AA

AB

AA

AD

AA

BN

AG

AB

AC

AB

1 AK

1 AB

44

R-8270

PARTS LIST


MISCELLANEOUS

Broiling trivet H : 50mm

Broiling rack H : 90mm

Cook-book

Operation manual

High voltage wire A

High voltage wire B

Main wire harness

Caution label

Name plate

Thermister harness

Wire holder (WH-1, “L”)

6- 1

6- 2

6- 3

6- 4

6- 5

AS

AS

AS

AK

AD

AD

AX

AC

AD

AN

AA

FAMi-0026WRKO

FAMi-0027WRKO

TCADCA048WRRO

TiNSEA169WRRO

QW-QZA013WREO

QW-QZ0130WREO

FW-VZA163WREO

TCAUH0114WRRO

TSPCNA280WRRO

FW-VZAl 93WRE0

LBNDK0012YBEO

6- 6

6- 7

6- 8

6- 9

6-10

6-1 1

SCREWS, NUTS, WASHERS AND RING

7- 1 LX-BZ0141WREO Screw ; monitor switch lever mtg 1 AA

7- 2 LX-BZ0186WREO Screw ; turntable motor cover, transformer for control unit, 5 AA

1 AA

8 AA

17 AA

capacitor holder and earthing

Screw ; open lever mtg

Screw ; outer case cabinet mtg

Screw ; unit chassis, pully cover, rear cabinet, control

panel back plate, electric parts mounting bracket

and fan duct assembly mtg

Screw ; outer case cabinet mtg

Screw ; upper and lower latch hook mtg

Screw ; fuse holder mtg

Screw ; damper switch mtg

Screw ; control unit and relay unit mtg

Screw ; heater wire mtg

Screw ; magnetron mtg

Screw ; power transformer mtg

Screw ; convection fan motor and fan motor mtg

Screw ; cord anchorage (upper) mtg

Screw ; waveguide cover and air duct mtg

Screw ; bearing mounting bracket mtg

Screw ; steam duct mtg

Screw ; oven lamp and latch plate mtg

Screw ; door frame mtg

Screw ; latch cover mtg

Screw ; cord anchorage (lower) mtg

Screw ; convection fan duct mtg

7- 3 LX-BZ0194WREO

7- 4 X~TSC40P12000

7- 5 LX-CZ0047WREO

7- 6 LX-EZOO46WREO

7- 7 LX-EZA004WREO

7- 8 XBPSD30Pl 2000

7- 9 XBPSD30Pl4KOO

7-10 LX-BZOl 98WRE0

AA

AA

AA

AA

AA

XBPSD30P08KSO

XBPSD50PlOKOO

XBPSDGOP12KSO

XBTSD40PlOOOO

XBTSD40P30000

XBTUW40P06000

XBTWW40P06000

XBTUW40PlOOOO

XCPSD30P08000

XCPSD30P06XOO

AA

AA

AA

AA

AA

7-11

7-12

7-13

7-14

7-15

7-l 6

7-17

7-18

7-19

7-20

AA

AA

AA

AA

AA

7-21 XCPSD40P08000

7-22 XCTSD40PlOOOO

7-23 XCPSD40P08000

AA

AA

AA

Note: THE VOLTAGE SUPPLIED TO THE PARTS MARKED “6” IS GREATER THAN 250V. 45

PARTS LIST


7-24 x C P S D 5 0 P 1 6 K S 0 Screw ; upper and lOWet oven hinge mtg 5 AA

7-25 x C T S D 4 0 P 0 8 0 0 0 Screw ; turntable motor mounting plate and thermal 4 AA

protection cover mtg

7-26 X C T S D 4 0 P 1 2 0 0 0 Screw ; base cabinet, rear cabinet and cord holder mtg 6 AA

7-27 X P N U W 6 0 --- 0 0 0 Pin ; convection fan pully mtg 1 AA

7-28 X F P S D 4 0 P 0 8 0 0 0 Screw ; turntable motor and damper motor mtg 4 AA

7-29 X F T S D 4 0 P 0 6 0 0 0 Screw ; bearing fixing plate mtg 3 AA

7-30 X F T S D 4 0 P 0 8 0 0 0 Screw ; magnetron air guide mtg 1 AA

7-31 X C T WW 4 0 P 1 2 0 0 0 Screw ; convection heater insulator (A) mtg 2 AA

7-32 X T T S D 4 0 P 1 2 0 0 0 Screw ; chassis support, key unit angle, steam duct, fan duct 4 AA

ass’y and control panel back plate mtg

7-33 LX-NZ0070WREO Nut;openlevermtg 1 AA

7-34 X N E S D 4 0 - 3 2 0 0 0 Nut ; cord anchorage and steam duct mtg 9 AA

7-35 XNEUW40-32000 Nut;convectionfanmtg 1 AA

7-36 X C B U W 3 0 P 0 6 0 0 0 Screw ; thermister mtg 2 AA

7-37 X W H U W 4 5 -0 8 1 2 0 Washer ; convection fan mtg 1 AA

7-38 X W S U W 4 0 - 1 0 0 0 0 Washer ; convection fan mtg 1 AA

7-39 X WW S D 6 0 - 0 8 0 0 0 Washer ; power transformer mtg 1 AA

7-40 X R S S P 1 2 - 0 4 0 0 0 Ring ; turntable coupling mtg I AA

7-41 X F P S D 4 0 P 0 8 K 0 0 Screw ; rectifier mtg 1 AA

7-42 X W H E Z 1 2 - 0 5 3 0 0 Ring ; turntable coupling mtg 1 AA

7-43 X P N S D 6 O---O 0 0 Pin ; motor pully mtg 1 AA

HOW TO ORDER REPLACEMENT PARTS

To have your order filled promptly and correctly, please furnish the following information

1. MODEL NUMBER 2. REF. NO.

3. PART NO. 4. DESCRIPTION

46

R-8270

REPLACEMENT PARTS LIST

This replacement parts list shows interchangeability of marked (*) parts on the control panel parts to the alterations of product

locations.

This list has been prepared to show LISTED PART NO. along with the USED PART NO. side by side.

REF. NO.

C3 etc.

c4

C5 etc.

c9

Cl0

c30

C80

C81

D7 etc.

D8 etc.

Ql

Q30 etc.

Q80

Q82

LISTED PART NO.

RC-EZA059DREO

RC-EZAOG 1 DREO

RC-KZA004DREO

RC-EZA057DREO

RC-EZA058DREO

RC-EZAOGODREO

RC-EZA063DREO

RC-EZA062DREO

RH-DZA002DREO

RH-DZAOl 1 DREO

RH-TZA008DREO

RH-TZA022DREO

RH-TZA025DREO

RH-TZA02 1 DREO

USED PART NO.

RC-EZTl06AFl E

RC-EZT475AFl H

VCKYATl EX153N

RC-EZT107AFlC

RC-EZT226AFl E

RC-EZT476AFlC

RC-EZT474AFl H

RC-EZT335AFl H

VHDUS1060ll-1

VHD1lElIIII-1

VS2SA885-Q/-l

VSDTA-143-A-l

VSZSC2021 / ilA

VS2SB851Ri l-1

REF. NO.

Rl

R2

R3

R4

R22 etc.

R23 etc.

R30

R66 etc.

R70 etc.

R81 etc.

R83

R84

R200

LISTED PART NO. / USED PART NO.

RR-DZ331NDREO VRD-STZEF331J

RR-DZl51 PDREO VRD-ST2HA151 J

RR-DZ121 PDREO VRD-ST2HAl21 J

RR-DZ271PDREO VRD-ST2HA271J

RR-DZ473NDREO VRD-ST2EF473J




RR-DZ273NDREO VRD-STZEF273J

RR-DZ103NDREO VRD-STZEFlO3J




47

R-8270

1 I 2 3 1 / 4 I 5 / 6

A

B

C

D

E

F

G

H

L

CABINET PARTS

1 I 2 I 3 I 4 5 I 6

48

R-8270

1 I 2 I 3 4 I 5 I 6 1

OVEN PARTS

1.3 $

1

% cn QC3 j.-

ALi/-

.-I, \_I ,

r< .-t . .

R-8270

A

B

C

D

E

F

G

I

H

1 I 2 3 I 4 I 5 I 6

A CONTROL PANEL PARTS

DOOR PARTS

t

1 I 2 I 3 I 4 5 I 6

t

If

50

R-8270

MISCELLANEOUS

Q 6- I

1 I 2 I 3 4 I 5 I 6

0 6-2 A

B

I

C

@-

D

v

E

llOlLlNG TRIVET PACKING ADD KIT IROILING PICK *

\ ,cmD8A-w

F

PACKING AND ACCESSORIES

TUIWTAILE ROLLER

Y TM” PACWWG FOAM x I

l Nor Replaceable Iterm

I

1 I 2 I 3 I 4 I 5 I 6

51

R-8270

SERVICE INFORMATION FOR TOUCH CONTROL UNIT

NOTE: ON REPLACEMENT OF ICl (RH-iX2429DREO: LSI)

1) As having mistakes on foil side of PWB NOS. Fl 112DR and F1112YA , we cut pins 51 and 52 of ICI related

to them and insert.

Accordingly, on repairing control unit PWB adjusted as above, cut pins 51 and 52 of ICI and insert in the same way.

2) From PWB Nos. Fl 112DR andF1112YA onward it is adjusted. Repair control unit PWB, therefore, inserting ICI

as it is.

52

SHARP

86 0 SHARP CORP. (7K0.8El Printed in Japan

sharp_r-8270.pdf

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